Pneumatic pressure controls are widely known and practiced in many forms in pneumatically powered and controlled systems. These systems usually require a constant predetermined pressure of a pneumatic medium, typically air, from a constant or varying input pressure source. Generally, a pneumatic pressure control device is composed of an inlet port, an outlet port, a valve control for communicating the inlet port with the outlet port when in a first position and providing an air tight seal between the inlet port and the outlet port when in a second position, and a regulator for controlling communication of the inlet port to the outlet port. In operation, when the outlet pressure drops below the predetermined pressure set in the regulator, the piston is engaged and the inlet port is connected to the outlet port until the outlet pressure reaches the predetermined pressure. Once the predetermined pressure is reached, the piston opens the seal between the outlet and inlet ports.
In manufacturing the air pressure control device, typically, a blank is cast and machined to form chambers and passages through which the pneumatic medium flows. Plugs, pistons and other parts needed to control flow and pressure are then formed and installed in the device. Machining the chambers and passages requires considerable cost and, consequently, if reduced without affecting quality, could reduce the cost of manufacturing the pneumatic pressure control device.
The present invention provides an insert that is formed such that when inserted in a bore machined into a blank, the insert and the bore mate to form the chambers and passages needed for pressure regulation. Preforming the insert to be subsequently mated with the bore reduces the amount of machining needed for the pressure control device, reduces the amount of assembly of the individual parts of the device, and thus reduces the cost of manufacturing the device.